Clinical significance of recurrent gastroesophageal junction intestinal metaplasia after endoscopic eradication of Barrett's esophagus

BACKGROUND AND AIMS

After endoscopic eradication of Barrett's esophagus (BE), recurrence of intestinal metaplasia at the gastroesophageal junction (GEJIM) is common. The clinical significance of this finding is unclear. We assessed whether recurrent GEJIM is associated with increased risk of subsequent dysplasia and whether endoscopic treatment lowers this risk.

METHODS

A retrospective, multicenter, cohort study was performed of treated BE patients who achieved complete eradication of intestinal metaplasia (IM). Postablation follow-up was performed at standard intervals. Recurrent GEJIM was defined as nondysplastic IM on gastroesophageal junction biopsy specimens without endoscopic evidence of BE. Patients were categorized as "never-GEJIM," "GEJIM-observed," or "GEJIM-treated." Endoscopic treatment for recurrent GEJIM was at the endoscopists' discretion. The primary outcome was dysplasia recurrence. Analyses were performed using log-rank tests and Cox proportional hazards modeling.

RESULTS

Six hundred thirty-three patients were analyzed; median follow-up was 47 months (interquartile range, 24-69). Most patients (81%) had high-grade dysplasia or intramucosal adenocarcinoma before treatment. Dysplasia recurrence was 2.2% per year. GEJIM-observed patients had the lowest rate of recurrence (.6%/y) followed by GEJIM-treated (2.2%/y) and never-GEJIM (2.6%/y) (log-rank P = .07). In multivariate analyses, compared with never-GEJIM, the risk of dysplasia recurrence was significantly lower in GEJIM-observed patients (adjusted hazard ratio, .19; 95% confidence interval, .05-.81) and not different in GEJIM-treated patients (adjusted hazard ratio, .81; 95% confidence interval, .39-1.67). Older age and longer initial BE length were independently associated with recurrence.

CONCLUSIONS

Recurrent GEJIM after endoscopic eradication of BE was not associated with an increased risk of subsequent dysplasia. Future studies are warranted to determine if observation is appropriate for this finding.

New onset diabetes predicts progression of low risk pancreatic mucinous cysts

BACKGROUND

Patients with low-risk lesions require ongoing surveillance since the rate of progression to pancreatic cancer (PC), while small, is much greater than in the general population. Our objective was to study the relationship between new onset diabetes (NODM) and progression in patients with low risk mucinous cysts.

METHODS

We evaluated a prospectively maintained cohort of 442 patients with a suspected mucinous cyst without worrisome features (WF) or high-risk stigmata (HRS). Multivariable Cox models were developed for progression to WF and HRS, with diabetes status formulated as both time independent and dependent covariates. The adjusted cumulative risk of progression was calculated using the corrected group prognosis method.

RESULTS

The 5-year cumulative progression rates to WFs and HRS were 12.8 and 3.6%, respectively. After controlling for other risk factors, the development of NODM was strongly associated with progression to HRS (HR = 11.6; 95%CI, 3.5-57.7%), but not WF. Among patients with the smallest cysts (<10 mm) at baseline, those who developed NODM had a 5-year adjusted cumulative risk of progression to HRS of 8.6% (95%CI, 0.0%-20.2%), compared to only 0.8% (95%CI, 0.0%-2.3%) for patients without NODM. Among patients with the largest cysts (20-29 mm), those who developed NODM during surveillance had a 5-year adjusted cumulative risk of progression of 53.5% (95%CI, 19.6%-89.9%) compared to only 7.5% (95%CI, 1.6%-15.2%) for patients without NODM.

CONCLUSION

New onset diabetes may predict progression in patients with low risk mucinous cysts. Pending validation with large-scale studies, these findings support regular diabetes screening among patients surveilled for suspected IPMNs or MCNs.

Endoscopic Ultrasound-Guided Fine Needle Biopsy Needles Provide Higher Diagnostic Yield Compared to Endoscopic Ultrasound-Guided Fine Needle Aspiration Needles When Sampling Solid Pancreatic Lesions: A Meta-Analysis

Background/Aims

Studies comparing the utility of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) for solid pancreatic lesions have been inconclusive with no clear superiority. The aim of this meta-analysis was to compare the diagnostic accuracy and safety between the two sampling techniques.

Methods

We performed a systematic search of randomized controlled trials published between 2012 and 2019. The primary outcome was overall diagnostic accuracy. Secondary outcomes included adverse event rates, cytopathologic and histopathologic accuracy, and the mean number of passes required to obtain adequate tissue between FNA and FNB needles. Fixed and random effect models with pooled estimates of target outcomes were developed.

Results

Eleven studies involving 1,365 participants were included for analysis. When compared to FNB, FNA had a significant reduction in diagnostic accuracy (81% and 87%, p=0.005). In addition, FNA provided reduced cytopathologic accuracy (82% and 89%, p=0.04) and an increased number of mean passes required compared to FNB (2.3 and 1.6, respectively, p<0.0001). There was no difference in adverse event rate between FNA and FNB needles (1.8% and 2.3% respectively, p=0.64).

Conclusions

FNB provides superior diagnostic accuracy without compromising safety when compared to FNA. FNB should be readily considered by endosonographers when evaluating solid pancreatic masses.

Diagnosis of Pancreatic Cystic Lesions by Virtual Slicing: Comparison of Diagnostic Potential of Needle-Based Confocal Laser Endomicroscopy versus Endoscopic Ultrasound-Guided Fine-Needle Aspiration

Background:

Pancreatic cystic lesions are often challenging entities for diagnosis and management. EUS-FNA diagnostic accuracy is limited by paucicellularity of cytology specimens and sampling errors. Needle-based confocal laser endomicroscopy (nCLE) provides real-time imaging of the microscopic structure of the cystic lesion and could result in a more accurate diagnosis.

Aims and Objectives:

To determine the diagnostic utility of in vivo nCLE and EUS-FNA in the diagnosis and histologic characterization of pancreatic cystic lesions (PCL).

Materials and Methods:

All patients diagnosed with PCL who had undergone nCLE and FNA over a 10-year period within a major urban teaching hospital were included in this study. All gastroenterology reports of the nCLE images and corresponding pathologist findings from the EUS-FNA were collected and compared with, a final diagnosis prospectively collected from clinicopathological and imaging data.

Results:

A total of n=32 patients were included in this study, which consisted of n=13 serous cystadenoma (SCA), n=7 intraductal papillary mucinous neoplasms (IPMN), n=2 mucinous cystic neoplasms (MCN), n=3 well-differentiated neuroendocrine tumors, n=2 cysts, n=2 benign pancreatic lesions, n=1 adenocarcinoma, n=1 gastrointestinal stromal tumor (GIST) and n=1 lymphangioma. The overall diagnostic rate was higher in nCLE (87.5%) vs. EUS-FNA (71.9%) While the diagnostic accuracy of nCLE and EUS-FNA were comparable in characterization of benign vs. malignant lesions, the nCLE diagnosis demonstrated higher accuracy rate in identifying mucinous cystic neoplasms compared to EUS-FNA.

Conclusion:

nCLE is a useful companion diagnostic tool for pancreatic cystic lesions and could assist the cytopathologist to better triage the sample for required ancillary testing and treatment planning. The combination of nCLE and EUS-FNA may be especially helpful in reducing the proportion of cases categorized as non-diagnostic.

Shorter time to achieve endoscopic eradication is not associated with improved long-term outcomes in Barrett's esophagus

Quality indicators have been proposed for endoscopic eradication therapy of Barrett's esophagus (BE). One such measure suggests that complete eradication of intestinal metaplasia (CE-IM) should be achieved within 18 months of starting treatment. The aim of this study was to assess whether achievement of CE-IM within 18 months is associated with improved long-term clinical outcomes. This was a retrospective cohort study of BE patients who underwent endoscopic eradication. Time to CE-IM was recorded and categorized as ≤ or > 18 months. The main outcome measures were recurrence of IM and of dysplasia after CE-IM, defined as a single endoscopy without endoscopic evidence of BE or histologic evidence of intestinal metaplasia. Recurrence was analyzed using the Kaplan-Meier method and multivariable Cox proportional hazards modeling. A total of 290 patients were included in the analyses. The baseline histology was high-grade dysplasia or intramucosal carcinoma in 74.2% of patients. CE-IM was achieved in 85.5% of patients, and 54.1% of the cohort achieved CE-IM within 18 months. Achieving CE-IM within 18 months was not associated with reduced risk of recurrence of IM or dysplasia in both unadjusted and adjusted analyses. In this cohort, older age and increased BE length were associated with IM recurrence, and increased hiatal hernia size was associated with dysplasia recurrence. Compared to longer times, achieving CE-IM within 18 months was not associated with a reduced risk of recurrence of IM or dysplasia. Alternative evidence-based quality metrics for endoscopic eradication therapy should be identified.

The Role of Endoscopic Ultrasound-Guided Ki67 in the Management of Non-Functioning Pancreatic Neuroendocrine Tumors

BACKGROUND/AIMS

The management of small, incidentally discovered nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) has been a matter of debate. Endoscopic ultrasound with fine-needle aspiration (EUS-FNA) is a tool used to identify and risk-stratify PNETs. This study investigates the concordance rate of Ki67 grading between EUS-FNA and surgical pathology specimens in NFPNETs and whether certain NF-PNET characteristics are associated with disease recurrence and disease-related death.

METHODS

We retrospectively reviewed the clinical history, imaging, endoscopic findings, and pathology records of 37 cases of NFPNETs that underwent pre-operative EUS-FNA and surgical resection at a single academic medical center.

RESULTS

There was 73% concordance between Ki67 obtained from EUS-FNA cytology and surgical pathology specimens; concordance was the highest for low- and high-grade NF-PNETs. High-grade Ki67 NF-PNETs based on cytology (p=0.028) and histology (p=0.028) were associated with disease recurrence and disease-related death. Additionally, tumors with high-grade mitotic rate (p=0.005), tumor size >22.5 mm (p=0.104), and lymphovascular invasion (p=0.103) were more likely to have poor prognosis.

CONCLUSION

NF-PNETs with high-grade Ki67 on EUS-FNA have poor prognosis despite surgical resection. NF-PNETs with intermediate-grade Ki67 on EUS-FNA should be strongly considered for surgical resection. NF-PNETs with low-grade Ki67 on EUSFNA can be monitored without surgical intervention, up to tumor size 20 mm.

The Utility of Endoscopic Ultrasound in Patients with Isolated Elevations in Serum Amylase and/or Lipase

BACKGROUND/AIMS

The aim of this study was to describe the diagnostic yield of endoscopic ultrasound (EUS) in patients with isolated elevated levels of amylase and/or lipase.

METHODS

A retrospective chart review was conducted at a large academic medical center from 2000 to 2016. Patients were selected based on having elevated amylase, lipase, or both, but without a diagnosis of pancreatitis or known pancreatobiliary disease. Patients were excluded if they had abnormal liver function tests or abnormal imaging of the pancreas.

RESULTS

Of 299 EUS procedures performed, 38 met inclusion criteria. Symptoms were present in 31 patients, most frequently abdominal pain (87%). In 20 patients (53%), initial EUS most commonly found chronic pancreatitis (n=7; 18%), sludge (5; 13%), or new diagnosis of pancreas divisum (3; 8%). In the asymptomatic patients (7), 3 had a finding on EUS, most importantly sludge (2), stone (1), and pancreas divisum (1). No patients were diagnosed with a mass or pancreatic cyst. During the follow up period, 6 patients (22%) had cholecystectomy.

CONCLUSION

In our study of patients with isolated elevations in amylase and/or lipase without acute pancreatitis who underwent EUS, approximately 50% had a pancreatobiliary finding, most commonly chronic pancreatitis or biliary sludge.

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice

BACKGROUND & AIMS

It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence.

METHODS

We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs.

RESULTS

By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate).

CONCLUSIONS

In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416.

The Role of Endotherapy in Recurrent Acute Pancreatitis

Patients with recurrent acute pancreatitis (RAP) have few treatment options available to them to manage their symptoms or prevent progression to chronic pancreatitis. At present, endotherapy is typically pursued as a means to achieve symptom remission and reduce rates of recurrence, hospitalization, abdominal pain, narcotic use, and surgical intervention. However, evidence that endotherapy effectively alters the natural history of disease remains limited. This article reviews the recent literature on the efficacy of endoscopic intervention in the treatment RAP with a focus on high-quality prospective randomized controlled studies. Additional studies are needed to corroborate these findings.

Comparison of Endoscopic Ultrasound-Fine-Needle Aspiration and Endoscopic Ultrasound-Fine-Needle Biopsy for Solid Lesions in a Multicenter, Randomized Trial

BACKGROUND & AIMS

Endoscopic ultrasound with fine-needle aspiration (FNA) is the standard of care for tissue sampling of solid lesions adjacent to the gastrointestinal tract. Fine-needle biopsy (FNB) may provide higher diagnostic yield with fewer needle passes. The aim of this study was to assess the difference in diagnostic yield between FNA and FNB.

METHODS

This is a multicenter, prospective randomized clinical trial from 6 large tertiary care centers. Patients referred for tissue sampling of solid lesions were randomized to either FNA or FNB of the target lesion. Demographics, size, location, number of needle passes, and final diagnosis were recorded.

RESULTS

After enrollment, 135 patients were randomized to FNA (49.3%), and 139 patients were randomized to FNB (50.7%).The following lesions were sampled: mass (n = 210, 76.6%), lymph nodes (n = 46, 16.8%), and submucosal tumors (n = 18, 6.6%). Final diagnosis was malignancy (n = 192, 70.1%), reactive lymphadenopathy (n = 30, 11.0%), and spindle cell tumors (n = 24, 8.8%). FNA had a diagnostic yield of 91.1% compared with 88.5% for FNB (P = .48). There was no difference between FNA and FNB when stratified by the presence of on-site cytopathology or by type of lesion sampled. A median of 1 needle pass was needed to obtain a diagnostic sample for both needles.

CONCLUSIONS

FNA and FNB obtained a similar diagnostic yield with a comparable number of needle passes. On the basis of these results, there is no significant difference in the performance of FNA compared with FNB in the cytologic diagnosis of solid lesions adjacent to the gastrointestinal tract. ClinicalTrials.gov identifier: NCT01698190.

Comparison of the diagnostic accuracy of three current guidelines for the evaluation of asymptomatic pancreatic cystic neoplasms

Asymptomatic pancreatic cysts are a common clinical problem but only a minority of these cases progress to cancer. Our aim was to compare the accuracy to detect malignancy of the 2015 American Gastroenterological Association (AGA), the 2012 International Consensus/Fukuoka (Fukuoka guidelines [FG]), and the 2010 American College of Radiology (ACR) guidelines.We conducted a retrospective study at 3 referral centers for all patients who underwent resection for an asymptomatic pancreatic cyst between January 2008 and December 2013. We compared the accuracy of 3 guidelines in predicting high-grade dysplasia (HGD) or cancer in resected cysts. We performed logistic regression analyses to examine the association between cyst features and risk of HGD or cancer.A total of 269 patients met inclusion criteria. A total of 228 (84.8%) had a benign diagnosis or low-grade dysplasia on surgical pathology, and 41 patients (15.2%) had either HGD (n = 14) or invasive cancer (n = 27). Of the 41 patients with HGD or cancer on resection, only 3 patients would have met the AGA guideline's indications for resection based on the preoperative cyst characteristics, whereas 30/41 patients would have met the FG criteria for resection and 22/41 patients met the ACR criteria. The sensitivity, specificity, positive predictive value, negative predictive value of HGD, and/or cancer of the AGA guidelines were 7.3%, 88.2%, 10%, and 84.1%, compared to 73.2%, 45.6%, 19.5%, and 90.4% for the FG and 53.7%, 61%, 19.8%, and 88% for the ACR guidelines. In multivariable analysis, cyst size >3 cm, compared to ≤3 cm, (odds ratio [OR] = 2.08, 95% confidence interval [CI] = 1.11, 4.2) and each year increase in age (OR = 1.07, 95% CI = 1.03, 1.11) were positively associated with risk of HGD or cancer on resection.In patients with asymptomatic branch duct-intraductal papillary mucinous neoplasms or mucinous cystic neoplasms who underwent resection, the prevalence rate of HGD or cancer was 15.2%. Using the 2015 AGA criteria for resection would have missed 92.6% of patients with HGD or cancer. The more "inclusive" FG and ACR had a higher sensitivity for HGD or cancer but lower specificity. Given the current deficiencies of these guidelines, it will be important to determine the acceptable rate of false-positives in order to prevent a single true-positive.

Mutation Profile and Fluorescence In Situ Hybridization Analyses Increase Detection of Malignancies in Biliary Strictures

BACKGROUND & AIMS

It is a challenge to detect malignancies in biliary strictures. Various sampling methods are available to increase diagnostic yield, but these require additional procedure time and expertise. We evaluated the combined accuracy of fluorescence in situ hybridization (FISH) and polymerase chain reaction-based DNA mutation profiling (MP) of specimens collected using standard brush techniques.

METHODS

We performed a prospective study of 107 consecutive patients treated for biliary strictures by endoscopic retrograde cholangiopancreatography from June 2012 through June 2014. We performed routine cytology and FISH analyses on cells collected by standard brush techniques, and analyzed supernatants for point mutations in KRAS and loss-of-heterozygosity mutations in tumor-suppressor genes at 10 loci (MP analysis was performed at Interpace Diagnostics). Strictures were determined to be nonmalignant based on repeat image analysis or laboratory test results 12 months after the procedure. Malignant strictures were identified based on subsequent biopsy or cytology analyses, pathology analyses of samples collected during surgery, or death from biliary malignancy. We determined the sensitivity and specificity with which FISH and MP analyses detected malignancies using the exact binomial test.

RESULTS

Our final analysis included 100 patients; 41% had biliary malignancies. Cytology analysis identified patients with malignancies with 32% sensitivity and 100% specificity. Addition of FISH or MP results to cytology results increased the sensitivity of detection to 51% (P < .01) without reducing specificity. The combination of cytology, MP, and FISH analyses detected malignancies with 73% sensitivity (P < .001). FISH identified an additional 9 of the 28 malignancies not detected by cytology analysis, and MP identified an additional 8 malignancies. FISH and MP together identified 17 of the 28 malignancies not detected by cytology analysis.

CONCLUSIONS

Addition of FISH and mutation analyses to cytology analysis significantly increased the level of sensitivity with which we detected malignancy in biliary strictures, with 100% specificity. These techniques can be performed using standard brush samples collected during endoscopic retrograde cholangiopancreatography, with mutations detected in free DNA in supernatant fluid of samples. The tests are complementary and therefore should be used sequentially in the diagnostic evaluation of biliary strictures.

A Multicenter Study of a Fluorescence In Situ Hybridization Probe Set for Diagnosing High-Grade Dysplasia and Adenocarcinoma in Barrett's Esophagus

BACKGROUND AND AIMS

Preliminary single-institution data suggest that fluorescence in situ hybridization (FISH) may be useful for detecting high-grade dysplasia (HGD) and esophageal adenocarcinoma (EA) in patients with Barrett's esophagus (BE). This multicenter study aims to validate the measurement of polysomy (gain of at least two loci) by FISH as a way to discriminate degrees of dysplasia in BE specimens.

METHODS

Tissue specimens were collected from four different hospitals and read by both the local pathology department ("Site diagnosis") and a single central pathologist ("Review diagnosis") at a separate institution. The specimens then underwent FISH analysis using probes 8q24 (MYC), 9p21 (CDKN2A), 17q12 (ERBB2), and 20q13 (ZNF217) for comparison. A total of 46 non-BE, 42 non-dysplastic specialized intestinal metaplasia (SIM), 23 indefinite-grade dysplasia (IGD), 10 low-grade dysplasia (LGD), 29 HGD, and 42 EA specimens were analyzed.

RESULTS

We found that polysomy, as detected by FISH, was the predominant chromosomal abnormality present as dysplasia increased. Polysomy was also the best predictor for the presence of dysplasia or EA when comparing its area under the curve to that of other FISH abnormalities. We observed that if at least 10% of cells had polysomy within a specimen, the FISH probe was able to differentiate between EA/HGD and the remaining pathologies with a sensitivity of 80% and a specificity of 88%.

CONCLUSIONS

This study demonstrates that using FISH to determine the percentage of cells with polysomy can accurately and objectively aid in the diagnosis of HGD/EA in BE specimens.

Endoscopic Therapy With Lumen-apposing Metal Stents Is Safe and Effective for Patients With Pancreatic Walled-off Necrosis

BACKGROUND & AIMS

Endoscopic ultrasound-guided transmural drainage and necrosectomy have become the standard treatment for patients with pancreatic walled-off necrosis (WON). Lumen-apposing metal stents (LAMS) have shown success in the management of pancreatic fluid collections. However, there are few data on their specific roles in management of WON. We investigated the efficacy and safety of LAMS in treatment of WON.

METHODS

We performed a retrospective multicenter case series of 124 patients with WON who underwent endoscopic transmural drainage by using LAMS at 17 tertiary care centers from January 2014 through May 2015. Patients underwent endoscopic ultrasound-guided cystogastrostomy or cystoenterostomy with placement of an LAMS into the WON collection. At the discretion of the endoscopist, we performed direct endoscopic necrosectomy, irrigation with hydrogen peroxide, and/or nasocystic drain placement. We performed endoscopic retrograde cholangiopancreatography with pancreatic duct stent placement when indicated. Concomitant therapies included direct endoscopic debridement (n = 78), pancreatic duct stent placement for leak (n = 19), hydrogen peroxide-assisted necrosectomy (n = 38), and nasocystic irrigation (n = 22). We collected data for a median time of 4 months (range, 1-34 months) after the LAMS placement. The primary outcomes were rates of technical success (successful placement of the LAMS), clinical success (resolution of WON, on the basis of image analysis, without need for further intervention via surgery or interventional radiology), and adverse events.

RESULTS

The median size of the WON was 9.5 cm (range, 4-30 cm). Eight patients had 2 LAMS placed for multiport access, all with technical success (100%). Clinical success was achieved in 107 patients (86.3%) after 3 months of follow-up. Thirteen patients required a percutaneous drain, and 3 required a surgical intervention to manage their WON. The stents remained patent in 94% of patients (117 of 124) and migrated in 5.6% of patients (7 of 124). The median number of endoscopic interventions was 2 (range, 1-9 interventions).

CONCLUSIONS

On the basis of a retrospective analysis of 124 patients, endoscopic therapy of WON by using LAMS is safe and effective. Creation of a large and sustained cystogastrostomy or cystoenterostomy tract is effective in the drainage and treatment of WON.

Progression of Incidental Intraductal Papillary Mucinous Neoplasms of the Pancreas in Liver Transplant Recipients

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant pancreatic cysts commonly found incidentally. Immunosuppression accelerates carcinogenesis.Thus, we aimed to compare IPMN progression in liver transplant (LT) recipients on chronic immunosuppression to progression among an immunocompetent population.

METHODS

We retrospectively assessed adult LT recipients between 2008 and 2014 for imaging evidence of IPMN. Diagnosis of IPMN was based on history, imaging, and cyst fluid analysis. The immunocompetent control group consisted of nontransplant patients from our pancreatic cyst surveillance program with IPMN under surveillance for greater than 12 months between 1997 and 2013. Four hundred fifty-four patients underwent LT in the study period and had cross-sectional imaging.

RESULTS

The prevalence of suspected IPMN was 6.6% (30 of 454). Compared with 131 controls, the transplant cohort was younger, with increased prevalence of diabetes and smoking. The prevalence of other risk factors for IPMN progression (history of pancreatitis, family history of pancreatic cancer) was similar. After an average follow-up of 31 months, most cysts increased in diameter, with a similar increase of dominant cyst (0.4 cm vs 0.5 cm; P = 0.6). Type of immunosuppression was not associated with the increased rate of cyst growth.

CONCLUSIONS

Our findings suggest that LT recipients with incidental IPMN can be managed under similar guidelines as immunocompetent patients.

The role of molecular analysis in the diagnosis and surveillance of pancreatic cystic neoplasms

CONTEXT

Molecular analysis of pancreatic cyst fluid obtained by EUS-FNA may increase diagnostic accuracy. We evaluated the utility of cyst-fluid molecular analysis, including mutational analysis of K-ras, loss of heterozygosity (LOH) at tumor suppressor loci, and DNA content in the diagnoses and surveillance of pancreatic cysts.

METHODS

We retrospectively reviewed the Columbia University Pancreas Center database for all patients who underwent EUS/FNA for the evaluation of pancreatic cystic lesions followed by surgical resection or surveillance between 2006-2011. We compared accuracy of molecular analysis for mucinous etiology and malignant behavior to cyst-fluid CEA and cytology and surgical pathology in resected tumors. We recorded changes in molecular features over serial encounters in tumors under surveillance. Differences across groups were compared using Student's t or the Mann-Whitney U test for continuous variables and the Fisher's exact test for binary variables.

RESULTS

Among 40 resected cysts with intermediate-risk features, molecular characteristics increased the diagnostic yield of EUS-FNA (n=11) but identified mucinous cysts less accurately than cyst fluid CEA (P=0.21 vs. 0.03). The combination of a K-ras mutation and ≥2 loss of heterozygosity was highly specific (96%) but insensitive for malignant behavior (50%). Initial data on surveillance (n=16) suggests that molecular changes occur frequently, and do not correlate with changes in cyst size, morphology, or CEA.

CONCLUSIONS

In intermediate-risk pancreatic cysts, the presence of a K-ras mutation or loss of heterozygosity suggests mucinous etiology. K-ras mutation plus ≥2 loss of heterozygosity is strongly associated with malignancy, but sensitivity is low; while the presence of these mutations may be helpful, negative findings are uninformative. Molecular changes are observed in the course of cyst surveillance, which may be significant in long-term follow-up.

Strategies for improving diagnostic accuracy of biliary strictures

BACKGROUND

Brush cytology is the initial intervention when evaluating biliary strictures. Biliary brush cytology is known for its low sensitivity (but high specificity) and may be accompanied by biopsies and/or fluorescent in situ hybridization (FISH) to improve diagnostic yield. This study aimed to identify features to enhance cytological sensitivity, and assess which sampling method(s) improve identification of pancreatobiliary adenocarcinomas (PBCa).

METHODS

Seventy-three biliary stricture cases were retrieved (38 PBCa and 35 control benign strictures). Biliary brushings, FISH, and biopsies were reviewed. Cytology specimens were evaluated for cellularity and presence of drunken honeycomb (DH), loosely cohesive clusters of round cells (LCCRC), large atypical cells with foamy cytoplasm (LACF), and single vacuolated malignant cells (SCs). Biopsies were examined for the presence of stromal invasion (SI).

RESULTS

Biliary brushings were scantly cellular in 47.4% of PBCa and 51.4% of controls, resulting in 69.6% nondiagnostic/false-negative cytology diagnoses. DH, LACF, and SCs were significantly associated with adenocarcinoma (P < .00001, .0033, and .00002, respectively). By univariate analysis, SCs and LACF were predictors of malignancy in brushings (P = .0002 and .05). By multivariate analysis, only SCs were predictive of malignancy (P = .002). SI facilitated the diagnosis in 9 biopsies. Sensitivity/specificity of brush cytology, FISH, and biopsy were 39.5%/94.3%, 63.9%/94.3%, and 84.2%/100%, respectively.

CONCLUSIONS

The low sensitivity of biliary brushings results from limited cellularity. Identification of LACF, DH, and SCs improves sensitivity. Sampling of stromal tissue may facilitate PBCa diagnosis. Concurrent biopsies and FISH are helpful in enhancing the diagnostic yield of PBCa.

Positive correlation between endoscopist radiofrequency ablation volume and response rates in Barrett's esophagus

BACKGROUND

Radiofrequency ablation (RFA) has become an accepted form of endoscopic treatment for Barrett's esophagus (BE), yet reported response rates are variable. There are no accepted quality measures for performing RFA, and provider-level characteristics may influence RFA outcomes.

OBJECTIVE

To determine whether endoscopist RFA volume is associated with rates of complete remission of intestinal metaplasia (CRIM) after RFA in patients with BE.

DESIGN

Retrospective analysis of longitudinal data.

SETTING

Three tertiary-care medical centers.

PATIENTS

Patients with BE treated with RFA.

INTERVENTION RFA MAIN OUTCOME MEASUREMENTS

For each endoscopist, we recorded RFA volume, defined as the number of unique patients treated as well as corresponding CRIM rates. We calculated a Spearman correlation coefficient relating these 2 measures.

RESULTS

We identified 417 patients with BE treated with RFA who had at least 1 post-RFA endoscopy with biopsies. A total of 73% of the cases had pretreatment histology of high-grade dysplasia or adenocarcinoma. The procedures were performed by 7 endoscopists, who had a median RFA volume of 62 patients (range 20-188). The overall CRIM rate was 75.3% (provider range 62%-88%). The correlation between endoscopist RFA volume and CRIM rate was strong and significant (rho = 0.85; P = .014). In multivariable analysis, higher RFA volume was significantly associated with CRIM (P for trend .04).

LIMITATIONS

Referral setting may limit generalizability. Limited number of endoscopists analyzed.

CONCLUSION

Endoscopist RFA volume correlates with rates of successful BE eradication. Further studies are required to confirm these findings and to determine whether RFA volume is a valid predictor of treatment outcomes in BE.

Fine-needle aspirations of pancreatic serous cystadenomas: improving diagnostic yield with cell blocks and α-inhibin immunohistochemistry

BACKGROUND

The diagnosis of serous cystadenoma (SCA), a rare benign pancreatic neoplasm, can alter the management of patients with pancreatic masses. Although characteristic imaging findings and fluid chemical analysis have been described, SCAs are not always recognized preoperatively. Furthermore, scant cellular yield on fine-needle aspiration (FNA) often leads to a nondiagnostic or nonspecific benign diagnosis. α-Inhibin (AI), a sensitive marker for SCA, is infrequently required for diagnosis in surgical specimens due to their characteristic histologic appearance. The objective of the current study was to determine whether AI staining can improve SCA diagnosis on FNA specimens.

METHODS

Fifteen confirmed cases of SCA with prior FNA specimens were selected for this study. FNAs were evaluated for cellularity, cellular arrangement, and cytomorphology. Resection specimens were reviewed.

RESULTS

Of the 15 FNA cases, approximately 75% demonstrated scant cellularity (11 of 15 cases). On smears, the cells were arranged as flat sheets, corresponding to strips of cells on cell block sections. The cells were small and round to cuboidal, with clear cytoplasm; occasional plasmacytoid cells and oncocytic cells were identified. Flattened cells, corresponding to attenuated epithelial cells lining macrocysts on the resections, were also noted. Stromal fragments were present in 5 FNAs and correlated with the hyalinized stroma in the resection specimens. AI immunostaining was positive in 88% of cases (7 of 8 of cases), thereby supporting the diagnosis of SCA.

CONCLUSIONS

The results of the current study indicate that low cellularity and bland cytology are inherent to SCAs. Performing cell blocks and AI staining on FNA specimens is useful for establishing the diagnosis of SCA. An immunohistochemical panel including AI, chromogranin, and synaptophysin may enhance the diagnostic accuracy of pancreatic FNA specimens.

Recurrence of esophageal intestinal metaplasia after endoscopic mucosal resection and radiofrequency ablation of Barrett's esophagus: results from a US Multicenter Consortium

BACKGROUND & AIMS

Radiofrequency ablation (RFA) is an established treatment for dysplastic Barrett's esophagus (BE). Although short-term end points of ablation have been ascertained, there have been concerns about recurrence of intestinal metaplasia (IM) after ablation. We aimed to estimate the incidence and identify factors that predicted the recurrence of IM after successful RFA.

METHODS

We analyzed data from 592 patients with BE treated with RFA from 2003 through 2011 at 3 tertiary referral centers. Complete remission of intestinal metaplasia (CRIM) was defined as eradication of IM (in esophageal and gastroesophageal junction biopsy specimens), documented by 2 consecutive endoscopies. Recurrence was defined as the presence of IM or dysplasia after CRIM in surveillance biopsies. Two experienced gastrointestinal pathologists confirmed pathology findings.

RESULTS

Based on histology analysis, before RFA, 71% of patients had high-grade dysplasia or esophageal adenocarcinoma, 15% had low-grade dysplasia, and 14% had nondysplastic BE. Of patients treated, 448 (76%) were assessed after RFA. Fifty-five percent of patients underwent endoscopic mucosal resection before RFA. The median time to CRIM was 22 months, with 56% of patients in CRIM by 24 months. Increasing age and length of BE segment were associated with longer times to CRIM. Twenty-four months after CRIM, the incidence of recurrence was 33%; 22% of all recurrences observed were dysplastic BE. There were no demographic or endoscopic factors associated with recurrence. Complications developed in 6.5% of subjects treated with RFA; strictures were the most common complication.

CONCLUSIONS

Of patients with BE treated by RFA, 56% were in complete remission after 24 months. However, 33% of these patients had disease recurrence within the next 2 years. Most recurrences were nondysplastic and endoscopically manageable, but continued surveillance after RFA is essential.

Detection of intestinal metaplasia after successful eradication of Barrett's Esophagus with radiofrequency ablation

BACKGROUND

Radiofrequency ablation (RFA) is an effective means of eradicating Barrett's esophagus (BE), both with and without associated dysplasia. Several studies have documented high initial success rates with RFA. However, there is limited data on IM detection rates after eradication.

AIMS

To determine the rate of detection of intestinal metaplasia (IM) after successful eradication of Barrett's esophagus.

METHODS

BE patients with and without dysplasia who had undergone RFA were retrospectively identified. Only those who had complete eradication as documented on the initial post-ablation endoscopy, and had minimum two surveillance endoscopies, were included in the analyses. Clinical, demographic, and endoscopic data were collected. Cumulative incidence of IM detection was calculated by the Kaplan-Meier method.

RESULTS

Forty-seven patients underwent RFA and had complete eradication of Barrett's epithelium. The majority of patients were male (76.6%), and the mean age was 64.2 years. The cumulative incidence of newly detected IM at 1 year was 25.9% (95% CI 15.1-42.1%). Dysplasia was detected at the time of recurrence in four patients, and all cases were detected at the GE junction in the absence of visible BE. Patients with recurrent IM had longer baseline segments of BE (median, 4 cm vs. 2 cm, p = 0.03).

CONCLUSIONS

The rate of detection of new IM is high in patients who have undergone successful eradication of BE by RFA. Additionally, dysplasia can recur at the GE junction in the absence of visible BE. Future studies are warranted to identify those patients at increased risk for the development of recurrent intestinal metaplasia.

A randomized trial comparing uncovered and partially covered self-expandable metal stents in the palliation of distal malignant biliary obstruction

BACKGROUND

The most common complication of uncovered biliary self-expandable metal stents (SEMSs) is tumor ingrowth. The addition of an impenetrable covering may prolong stent patency.

OBJECTIVE

To compare stent patency between uncovered and partially covered SEMSs in malignant biliary obstruction.

DESIGN

Multicenter randomized trial.

SETTING

Four teaching hospitals.

PATIENTS

Adults with inoperable distal malignant biliary obstruction.

INTERVENTIONS

Uncovered or partially covered SEMS insertion.

MAIN OUTCOME MEASURES

Time to recurrent biliary obstruction, patient survival, serious adverse events, and mechanism of recurrent biliary obstruction.

RESULTS

From October 2002 to May 2008, 129 patients were randomized. Recurrent biliary obstruction was observed in 11 of 61 uncovered SEMSs (18%) and 20 of 68 partially covered SEMSs (29%). The median times to recurrent biliary obstruction were 711 days and 357 days for the uncovered and partially covered SEMS groups, respectively (P = .530). Median patient survival was 239 days for the uncovered SEMS and 227 days for the partially covered SEMS groups (P = .997). Serious adverse events occurred in 27 (44%) and 42 (62%) patients in the uncovered and partially covered SEMS groups, respectively (P = .046). None of the uncovered and 8 (12%) of the partially covered SEMSs migrated (P = .0061).

LIMITATIONS

Intended sample size was not reached. Allocation to treatment groups was unequal.

CONCLUSIONS

There was no significant difference in time to recurrent biliary obstruction or patient survival between the partially covered and uncovered SEMS groups. Partially covered SEMSs were associated with more serious adverse events, particularly migration.

Low prevalence of submucosal invasive carcinoma at esophagectomy for high-grade dysplasia or intramucosal adenocarcinoma in Barrett's esophagus: a 20-year experience

BACKGROUND

The rate of occult adenocarcinoma at esophagectomy in patients with Barrett's esophagus (BE) and high-grade dysplasia (HGD) has been reported to be approximately 40%. Recently, it has been suggested that this risk may be overestimated.

OBJECTIVE

Our purpose was to determine the rate of submucosal invasive adenocarcinoma in patients undergoing esophagectomy for BE after biopsy diagnosis of HGD or intramucosal carcinoma (IMC). A secondary aim was to identify clinical risk factors for submucosal invasive adenocarcinoma in these patients.

DESIGN

A retrospective study.

SETTING

Tertiary referral center.

PATIENTS

All patients with preoperative BE with HGD or IMC treated with esophagectomy over a 20 year period.

INTERVENTIONS

Esophagectomy.

MAIN OUTCOME MEASUREMENTS

Submucosal invasive adenocarcinoma at esophagectomy.

RESULTS

Sixty patients were included (41 with preoperative HGD, 19 with preoperative IMC). The overall rate of submucosal invasive carcinoma was 6.7% (95% CI, 1.8%-16.2%) (n = 4), with a 5% rate of submucosal invasion in patients with preoperative HGD and 11% for patients with preoperative IMC. All 4 patients with submucosal invasion at esophagectomy had either nodular or ulcerated mucosa on preoperative endoscopy. The 1-year and 5-year all-cause risks of death for the entire cohort were 1.9% and 10.9%, respectively.

LIMITATIONS

Retrospective study.

CONCLUSIONS

The rate of submucosal invasive adenocarcinoma at esophagectomy in BE patients with HGD or IMC on biopsy is much lower than 40%. After adequate sampling and staging, patients with BE with HGD and IMC, especially those without endoscopically visible lesions, can potentially be treated by nonsurgical (local) therapies.

XRCC1 and XPD polymorphisms and esophageal adenocarcinoma risk

DNA damage is important in the pathogenesis of esophageal adenocarcinoma (EA). Polymorphic variants in DNA repair genes may be modifiers of the risk of EA through their role in altering human host response to gastroesophageal acid reflux, a well-described risk factor for EA. We studied the role of genetic polymorphisms of two key DNA repair genes, xeroderma pigmentosum group D (XPD) (Asp312Asn and Lys751Gln) in the nucleotide excision repair (NER) pathway and X-ray repair cross-complementing gene 1 (XRCC1) (Arg399Gln) in the base excision repair (BER) pathway, in the development of EA in 183 cases and 336 frequency-matched controls for age, gender and race. Genomic DNA was extracted from blood samples. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from logistic regression models, adjusted for body mass index at 18 years of age, smoking and alcohol exposure. The variant genotypes of XPD Lys751Gln polymorphism were associated with a higher risk of EA; the adjusted OR comparing Gln/Gln + Lys/Gln with Lys/Lys was 1.49 (95% CI: 1.02-2.14). Although no significant relationships were found for the XRCC1 Arg399Gln polymorphism alone, this polymorphism did modify the relationship between XPD Lys751Gln and EA risk; when both polymorphisms were evaluated together, adding the number of variant alleles of the two polymorphisms resulted in a significant trend (trend test, P = 0.008); compared with individuals with no variant alleles (n = 88), the adjusted ORs of developing EA are 1.49 (95% CI: 0.88-2.59), 1.69 (95% CI: 0.98-2.96) and 2.58 (95% CI: 1.31-5.06) for one (n = 195), two (n = 166) and three or four variant alleles (n = 70), respectively. No relationships were found for the XPD Asp312Asn polymorphism. We conclude that combined NER and BER pathways are important to the development of EA.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

Optical coherence tomography to identify intramucosal carcinoma and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Optical coherence tomography (OCT) is an optical technique that produces high-resolution images of the esophagus during endoscopy. OCT can distinguish specialized intestinal metaplasia (SIM) from squamous mucosa, but image criteria for differentiating intramucosal carcinoma (IMC) and high-grade dysplasia (HGD) from low-grade dysplasia (LGD), indeterminate-grade dysplasia (IGD), and SIM without dysplasia have not been validated. The purpose of this study was to establish OCT image characteristics of IMC and HGD in Barrett's esophagus.

METHODS

Biopsy-correlated OCT images were acquired from patients with Barrett's esophagus undergoing endoscopic surveillance. Two pathologists rendered consensus diagnoses of the biopsy specimens. A blinded investigator reviewed the biopsy-correlated OCT images and scored each for surface maturation and gland architecture. For each image the scores were summed to determine an OCT "dysplasia index."

RESULTS

A total of 177 biopsy-correlated images were analyzed. The corresponding histopathology diagnosis was IMC/HGD in 49 cases, LGD in 15, IGD in 8, SIM in 100, and gastric mucosa in 5. A significant relationship was found between a histopathologic diagnosis of IMC/HGD and scores for each image feature (dysplasia index [Spearman correlation coefficient, r = 0.50, P < .0001], surface maturation [r = 0.48, P < .0001], and gland architecture [r = 0.41, P < .0001]). When a dysplasia index threshold of >or=2 was used, the sensitivity and specificity for diagnosing IMC/HGD were 83% and 75%, respectively.

CONCLUSIONS

An OCT image scoring system based on histopathologic characteristics has the potential to identify IMC and HGD in Barrett's esophagus.

New frontiers in endoscopic imaging

Gastrointestinal (GI) tract malignancies have a tremendous impact on society. Colorectal cancer is the second leading cause of cancer death in the United States and accounts for 10% of all cancer deaths. Significant research efforts are being directed toward using the interaction of light and tissue to detect pre-cancerous lesions of the GI tract. This article reviews the current status of various experimental optical technologies to detect pre-cancerous changes in the GI tract and focuses on the clinical applications of these technologies for the practicing gastroenterologist.

EUS-guided fine needle aspiration of pancreatic cysts: a retrospective analysis of complications and their predictors

BACKGROUND AND AIMS

Endoscopic ultrasound-guided fine-needle aspiration (EUS FNA) of pancreatic cysts is considered safe, however, data are conflicting regarding complication rates. The aim of this study was to determine the complication rate of EUS-guided pancreatic cyst aspiration and predictors of these complications.

METHODS

Results of pancreatic cyst EUS FNA at 2 academic institutions from March 1996 to October 2003 were reviewed. A total of 603 patients with 651 pancreatic cysts were evaluated. Complications were identified from clinic, emergency department, and discharge notes, and laboratory and radiologic data. Data collected were as follows: cyst size, location, septations, diagnosis, number of passes, needle size, status as inpatient or outpatient, performance of same-day endoscopic retrograde cholangiopancreatography (ERCP), and use of prophylactic antibiotics.

RESULTS

Complications were identified in 13 patients (2.2%, 13 of 603): 6 patients had pancreatitis, 4 patients had abdominal pain, 1 patient had a retroperitoneal bleed, 1 patient had an infection, and 1 patient had bradycardia. Twelve patients required hospitalization, with an average length of stay of 3.8 +/- 1.1 days. Type of cyst, size, presence of septations or mass, and same-day ERCP were not predictors of complications.

CONCLUSIONS

EUS-guided pancreatic cyst aspiration carries a low complication rate similar to that reported for solid pancreatic lesions. No patient or cyst characteristics appear to be predictive of adverse events.

Diagnosis of Barrett's esophagus using optical coherence tomography

The presence of Barrett's esophagus (BE) is determined by histopathologic analysis of biopsy specimens obtained during upper endoscopy. The accuracy of endoscopy for the diagnosis of BE is surprisingly poor, however. Optical coherence tomography (OCT) is an optical technology that has shown promise as a powerful new tool to study BE. Of all the methods of optical biopsy discussed in this issue,perhaps OCT comes closest to this goal in that it provides a two dimensional image that correlates with traditional histopathologic excisional biopsy.

Temporally and spectrally resolved fluorescence spectroscopy for the detection of high grade dysplasia in Barrett's esophagus

BACKGROUND AND OBJECTIVES

Temporal and spectral fluorescence spectroscopy can identify adenomatous colonic polyps accurately. In this study, these techniques were examined as a potential means of improving the surveillance of high grade dysplasia (HGD) in Barrett's esophagus (BE).

STUDY DESIGN/MATERIALS AND METHODS

Using excitation wavelengths of 337 and 400 nm, 148 fluorescence spectra, and 108 transient decay profiles (at 550 +/- 20 nm) were obtained endoscopically in 37 patients. Corresponding biopsies were collected and classified as carcinoma, HGD, or low risk tissue (LRT) [non-dysplastic BE, indefinite for dysplasia (IFD), and low grade dysplasia (LGD)]. Diagnostic algorithms were developed retrospectively using linear discriminant analysis (LDA) to separate LRT from HGD.

RESULTS

LDA produced diagnostic algorithms based solely on spectral data. Moderate levels of sensitivity (Se) and specificity (Sp) were obtained for both 337 nm (Se = 74%, Sp = 67%) and 400 nm (Se = 74%, Sp = 85%) excitation.

CONCLUSIONS

In the diagnosis of HGD in BE, steady-state fluorescence was more effective than time-resolved data, and excitation at 400 nm excitation was more effective than 337 nm. While fluorescence-targeted biopsy is approaching clinical usefulness, increased sensitivity to dysplastic changes-possibly through modification of system parameters-is needed to improve accuracy levels.

Temporally and spectrally resolved fluorescence spectroscopy for the detection of high grade dysplasia in Barrett's esophagus

BACKGROUND AND OBJECTIVES

Temporal and spectral fluorescence spectroscopy can identify adenomatous colonic polyps accurately. In this study, these techniques were examined as a potential means of improving the surveillance of high grade dysplasia (HGD) in Barrett's esophagus (BE).

STUDY DESIGN/MATERIALS AND METHODS

Using excitation wavelengths of 337 and 400 nm, 148 fluorescence spectra, and 108 transient decay profiles (at 550 +/- 20 nm) were obtained endoscopically in 37 patients. Corresponding biopsies were collected and classified as carcinoma, HGD, or low risk tissue (LRT) [non-dysplastic BE, indefinite for dysplasia (IFD), and low grade dysplasia (LGD)]. Diagnostic algorithms were developed retrospectively using linear discriminant analysis (LDA) to separate LRT from HGD.

RESULTS

LDA produced diagnostic algorithms based solely on spectral data. Moderate levels of sensitivity (Se) and specificity (Sp) were obtained for both 337 nm (Se = 74%, Sp = 67%) and 400 nm (Se = 74%, Sp = 85%) excitation.

CONCLUSIONS

In the diagnosis of HGD in BE, steady-state fluorescence was more effective than time-resolved data, and excitation at 400 nm excitation was more effective than 337 nm. While fluorescence-targeted biopsy is approaching clinical usefulness, increased sensitivity to dysplastic changes-possibly through modification of system parameters-is needed to improve accuracy levels.

Diagnosis of Barrett's esophagus using optical coherence tomography

OCT is a promising optical technology that permits real-time, high-resolution, cross-sectional imaging of tissue during endoscopy. It has been shown to be a highly sensitive and specific means of identifying the presence of SIM. Preliminary studies suggest that OCT is capable of grading dysplasia occurring within BE and has the potential to assist with the staging of superficial malignancies, particularly squamous cell cancers. In the near future, the capabilities of OCT systems are expected to improve with systems capable of much higher resolution and with Doppler capability becoming available.

Detection of high-grade dysplasia in Barrett's esophagus by spectroscopy measurement of 5-aminolevulinic acid-induced protoporphyrin IX fluorescence

BACKGROUND

Preliminary studies with qualitative detection methods suggest that 5-aminolevulinic acid-induced protoporphyrin IX fluorescence might improve the detection of dysplastic Barrett's epithelium. This study used quantitative methods to determine whether aminolevulinic acid-induced protoporphyrin IX fluorescence can differentiate between Barrett's mucosa with and without dysplasia.

METHODS

Patients were given 10 mg/kg of aminolevulinic acid orally 3 hours before endoscopy. Quantitative fluorescence spectra were acquired by using a nitrogen-pumped dye laser (l 400 nm) spectrograph system. The protoporphyrin IX fluorescence intensity at 635 nm was compared with the histopathologic diagnosis for mucosal biopsy specimens taken immediately after the fluorescence measurements.

RESULTS

Ninety-seven spectra were obtained from 20 patients. The mean (+/- standard error) standardized protoporphyrin IX fluorescence intensity was significantly greater (p < 0.05) for high-grade dysplastic Barrett's epithelium (0.29 +/- 0.07, n = 13) than for nondysplastic Barrett's epithelium (0.11 +/- 0.02, n = 43). By using protoporphyrin IX fluorescence alone, high-grade dysplasia was distinguished from nondysplastic tissue types with 77% sensitivity and 71% specificity. Decreased autofluorescence was particularly found in nodular high-grade dysplasia. By using the fluorescence intensity ratio of 635 nm/480 nm, nodular high-grade dysplasia could be differentiated from nondysplastic tissue with 100% sensitivity and 100% specificity.

CONCLUSION

Protoporphyrin IX fluorescence may be useful for identifying areas of high-grade dysplasia in Barrett's esophagus and for targeting of biopsies.

Detection of high-grade dysplasia in Barrett's esophagus by spectroscopy measurement of 5-aminolevulinic acid-induced protoporphyrin IX fluorescence

BACKGROUND

Preliminary studies with qualitative detection methods suggest that 5-aminolevulinic acid-induced protoporphyrin IX fluorescence might improve the detection of dysplastic Barrett's epithelium. This study used quantitative methods to determine whether aminolevulinic acid-induced protoporphyrin IX fluorescence can differentiate between Barrett's mucosa with and without dysplasia.

METHODS

Patients were given 10 mg/kg of aminolevulinic acid orally 3 hours before endoscopy. Quantitative fluorescence spectra were acquired by using a nitrogen-pumped dye laser (l 400 nm) spectrograph system. The protoporphyrin IX fluorescence intensity at 635 nm was compared with the histopathologic diagnosis for mucosal biopsy specimens taken immediately after the fluorescence measurements.

RESULTS

Ninety-seven spectra were obtained from 20 patients. The mean (+/- standard error) standardized protoporphyrin IX fluorescence intensity was significantly greater (p < 0.05) for high-grade dysplastic Barrett's epithelium (0.29 +/- 0.07, n = 13) than for nondysplastic Barrett's epithelium (0.11 +/- 0.02, n = 43). By using protoporphyrin IX fluorescence alone, high-grade dysplasia was distinguished from nondysplastic tissue types with 77% sensitivity and 71% specificity. Decreased autofluorescence was particularly found in nodular high-grade dysplasia. By using the fluorescence intensity ratio of 635 nm/480 nm, nodular high-grade dysplasia could be differentiated from nondysplastic tissue with 100% sensitivity and 100% specificity.

CONCLUSION

Protoporphyrin IX fluorescence may be useful for identifying areas of high-grade dysplasia in Barrett's esophagus and for targeting of biopsies.

Optical coherence tomography of the biliary tree during ERCP

BACKGROUND

Optical coherence tomography (OCT) is a high-resolution imaging technique that produces cross-sectional images in vivo. This is a report of the first use of OCT to acquire images of the biliary tree during ERCP.

METHODS

A 2.6-mm diameter OCT catheter delivered through the accessory channel of a duodenoscope was used to acquire images of the intrahepatic and extrahepatic bile ducts in 5 patients. Histology-correlated OCT images of 5 cadaveric livers, each imaged at 3 sites, were used to guide interpretation of the in vivo images.

RESULTS

Biliary ductal epithelium and subepithelial structures, including peribiliary glands, vasculature, and hepatic parenchyma, were visualized in vivo. The papillary architecture of cholangiocarcinoma was identified by OCT. There were no OCT-related complications.

CONCLUSIONS

High-resolution OCT imaging of the biliary tree is feasible and may provide useful diagnostic information during ERCP.

Diagnosis of specialized intestinal metaplasia by optical coherence tomography

BACKGROUND AND AIMS

Optical coherence tomography (OCT) is an imaging technique that produces high-resolution cross-sectional images in vivo. The aim of this study was to establish the sensitivity and specificity of OCT for diagnosing specialized intestinal metaplasia (SIM).

METHODS

OCT was used to image the stomach and esophagus of 121 patients. A total of 288 biopsy-correlated OCT images were acquired. OCT criteria for SIM were formulated by analyzing 75 images of SIM. The SIM image criteria were retrospectively tested by applying them to images of gastric, squamous, SIM, and cardiac epithelium. The criteria were then tested prospectively to determine the sensitivity and specificity of OCT for diagnosing SIM.

RESULTS

OCT images of SIM are characterized by (1) absence of the layered structure of normal squamous epithelium and the vertical "pit and crypt" morphology of gastric mucosa, (2) disorganized architecture with inhomogeneous tissue contrast and an irregular mucosal surface, and (3) presence of submucosal glands. These criteria were 100% sensitive and 93% specific for SIM when applied retrospectively and 97% sensitive and 92% specific when tested prospectively.

CONCLUSIONS

OCT is highly sensitive and specific for SIM and may aid in the diagnosis and surveillance of this preneoplastic lesion.

Optical coherence tomography in the gastrointestinal tract

Optical coherence tomography (OCT) is a high-resolution, cross-sectional optical imaging technique that allows in situ imaging of tissue by measuring back-reflected light. OCT provides images in real time with a resolution approaching that of conventional histopathology, but without the need for tissue removal. OCT imaging can be performed endoscopically to visualize gastrointestinal tissue using a fiberoptic catheter passed through the instrument channel of a conventional endoscope. The resolution of OCT allows visualization of the different layers of gastrointestinal epithelium and the differentiation of Barrett's epithelium from normal gastric and squamous mucosa. OCT has also been used to image esophageal adenocarcinoma and colonic polyps. Recent developments include Doppler OCT, spectroscopic OCT, and ultrahigh-resolution OCT, which can visualize nuclei within single cells. Although still in its infancy as a clinical tool, OCT currently provides high-resolution images over the same imaging depth as conventional mucosal biopsy, and may prove to be a useful and minimally invasive technique for evaluating gastrointestinal tissue, particularly for early neoplastic changes.